Drivable hollow cable



May 253 1965 A. J. KOMPANEK, JR., ETAL 3,184,986

DRIVABLE HOLLOW CABLE Filed Feb. 2, 1962 United States Patent O :tissuesD'tlVAllLE HULLUW CABLE Andrew Il. Konipanelt, lr., and lllred Machete,Lansdale,

and George lvl. Eicher, Jr., King of Prussia, ha.,

assignors to 'lfeiellerr incorporated, North Wales, Pa.,

a corporation et? Delaware Filed Feb., 2, i962, Ser. No. 170,72@ 6Qlaims. (Ci. '7d-422) The present invention relates to a unique type ofcable formed in such a waykas to include an exteriorly convoluted wiremember formed throughout the cable length and which member is adapted tocoact with a gear type member so as to permit the cable to be driven ormoved relative to a surrounding and fixed conduit means.

More specically, the subject invention relates to a drivable cablemember which includes componen. uniquely formed to provide a hollowcable interior within which further tube or electrical cable member-sare adapted to be supported for transmitting a flow oi mattertherethrough. The subject hollow drivable cable is constructed in such away that any interiorly disposed electrical cable or tubular members aremovable therewith but are subjected to essentially no tensile orcompression leading.

rthe subject hollow cable is of general utility and the substantiallyload-free interiorly disposed wires or tubes may transmit electrical,pneumatic or hydraulic matter therethrough.

The present hollow drivable cable is to be clearly distinguished fromhollow conduits the latter which are adapted to movably receive a cableelement therewithin. Rather, the subject hollow cable construction isitself adapted to be movably disposed within such a hollow conduit whilethe cable non-movably retains within its hollow exterior non-loadbearing members which are 'adapted to transmit matter therewithin.

While drivable cables are, in general, well known such elements have inthe past been utilized so as to be directly connected to an operativeelement, c g. a gear, lever, etc. to actuate some mechanism. 0n theother hand, the subject cable is not limited to actua-tion of a remotemechanism but instead, or in addition, may be used to position acondition sensing or matter transmitting member in relation to Somesource. The source in turn, is adapted to be remotely controlled oractuated in accordance with the condition sensed or matter transmitted.

For instance, in order to accurately control a heat source such as afurnace or atomic reactor, it is necessary that a sensing device bemovable therewithin to indicate the interior temperatures of the heatsource whereby the heat level of the latter may be accuratelycontrolled. This type of control may be achieved by the variablepositioning of a thermocouple which transmits a temperature-inducedelectric current through lead lwires positioned within such adrivable'cable. inasmuch as such electrical lead wires are preferablynot load transmitting members, it is imperative that the driving cablebe designed in a way to transmit tension and compression loads whichoccur as a result of supporting the moving such a thermocouple or otherdevice.

Similarly, it may be desired to transmit or circulate fluid within someremote body in a manner requiring that such lluid be introduced at orwithdrawn from diiferent points again requiring the use of a drivablecable mernyber of a hollow construction such that the iluidmedium may betransmitted therethrough. n Y

lt is, therefore, a general object of the present invention to provideak hollow cable member capable of withstandingftension and compressionloads, adapted to in- 3,l84,98i Patented May 25, 1965 "ice teriorlysupport essentially non-load carrying matter transmitting members, andwhich cable also includes an exterior construction permitting a drivingmember to coact therewith to actuate said cable within a supportingconduit.

More speciiically, the subject drivable hollow cable includes ahelically coiled flat strip member adapted to withstand compressionloading, a plurality of tension transmitting long lay wires wrappedabout the more closely coiled strip member and an exteriorly disposedhelical wire the convolutions of which are longitudinally spaced togrippingly engage the long lay wires and which exterior wire is adaptedto coact with a driving member to impart movement to the cable.

inasmuch as longitudinal movement of the subject cable occurs throughthe application of a longitudinally applied force through the outerhelical wire member, it is also an object of the present invention toprovide means for insuring good gripping engagement between said wireand the subadjacent long lay wires.

The details as well as other objects and advantages ofthe presentinvention will be apparent from a perusal of the detailed descriptionwhich follows taken in conjunction with the drawings.

ln the drawings:

FlGURE l is a schematic representation of a control sys-tem embodyingthe subject hollow-drivable cable;

FGURE 2 is a view `showing the outer driving wire partially unwound toillustrate the gripping surface formed thereon;

FGURE 3 is aview along line 3 3 of FGURE. l;

FIGURE l is a modification showing a non-loadk bearing tube Within thesubject cable;

FIGURE 5 is a view along line 5'-5 .of FIGURE/l.

Throughout the description like parts are indicated by the sameidentifying numbers.

Referring to FGURE l, the subject drivable cable member is indicatedgenerally at lll' and is adapted to be longitudinally actuated, asindicated by the arrows, within a relatively fixed conduit i2. Thelongitudinal actuation of cable l@ may be achieved in any suitablemanner as by a rotatable gear member 14 adapted to coaot with the cablein a manner to be subsequently described.

Cable supporting conduit 12 may be of any suitable yconstruction and mayeither be rigid or eXible in accordance with particularrequirementsjbut, at any rate, the conduit is normally non-movablymounted relative to any particular installation with which it isemployed. Cable it? is slidably supported upon the interior suo face ofconduit l2.

Cable lil includes an inner coil member 16. Most preferably, inner coilmember llo is formed from aktlat narrow strip member having arectangular cross section and which is closely coiled with a very shorthelix such that the adjacent convolutions are normally abutting. As thusconstructed, inner coil 'lo is adapted to carry compression loadingparticularly as induced during longitudinal actuationof the cable.

Ftension loads on the cable ld are primarily withstood by a plurality ofrelatively long lay wires l laid about inner coil ld on a relativelylong helix. The number and closeness of long lay wires lil is generallydetermined by the tensile loads to which the cable is to be subjected.

lt is apparent that the closely coiled inner coil member le while ableto withstand compression loading, due to the column strength realizedthrough thelongitudinally abuttiip7 nature or" adjacent convolutions,rwould tend to stretch or uncoil in response to tension loads. @n tleother hand, the relatively small diameter long lay wires iiihave'relatively little column or compression strength but,

ena/asse i3 on the other hand, due to their long helix are able towithstand tension loading without significant uncoiling. Thus inner coil16 and long lay Wires 13 are closely wrapped together so as toconjointly withstand the compression and tension loads to which cable l@is subjected.

A relatively heavy wire 2li is tightly coiled about long lay wires 18 ona short helix but in which the adjacent convolutions of the wire arelongitudinally spaced. The space between the convolutions of wire Ztl isgenerally determined by the size and spacing of the coacting members onthe member adapted to drive cable More specically, the space between thewire convolutions in the illustration of FIGURE l is determined by thesize of the teeth 22 on driving gear ld. As seen in FIGURE l, as gear ldis rotated adjacent teeth will move between adjacent convolutions ofwire 2b to longitudinally drive cable lil.

Inasmuch as relatively high peripheral load forces may be transmittedfrom gear 14 to wire 2G, the latter must be a relatively stiff or heavymember. Accordingly, cable driving wire 2i) is preferably from two .tothree times the diameter of long lay wires 18.

At the same time, in order to insure accuracy in controlling thelongitudinal movement and positioning of cable itl, it is important thatthe convolutions of wire Ztl be equally and accurately spaced. Toillustrate the importance of such equal `and accurate spacing of thewire convolutions, let it be supposed that the space between one pair ofconvolutions was twice as much as the space between an adjacent pair ofwire convolutions. ln this event,

as the teeth 22 of gear i4 move between the disparate spaces a certainamount of gear movement will not be translated into cable movement. Inother words, there will be a limited amount of lost motion between thegear and the cable. It is further apparent that any such slippingbetween the driving member and the cable will result in an inaccuratepositioning 'of the cable and the device which it controls. The mannerand apparatus by which wire 20 is accurately laid about long lay wires155 is shown and described in copending application P-3l3 Machete.

In order to maintain the convolutions of wire Ztl equally spacedlongitudinally of the cable, as well as to insure good grippingengagement between the wire and the subadjacent long lay wires 18 and tothereby prevent longitudinal displacement of wire convolutions whensubjected to longitudinal loading by a cable driving member, such asgear 14, it has been found to be most advantageous to provide means forproviding a kind of interlocking or interfering engagement between theabutting surfaces of the driving wire 20 and long lay wires 18. To thisend, the inner surface of wire 2) adapted to abut subadjacent long laywires 18 is formed with serrations or indentations 24 thereon as bestseen in FGURES l and 2. The manner in which such serrations are formedon the driving wire is also shown and described in the aforenotedcoending application.

Serrations 24 are formed generally transversely of the longitudinal axisof wire 2d. Thus, the inner surface of the driving wire has a washboardeffect to interrupt the otherwise smooth character of such wire.

Thus as wire Ztl is rolled or laid about long lay wires 1S, serrationsor indentations 2d tend to interlock with long lay wires f8 and therebyresist relative sliding movement between the wire convolutions and thesubadjacent long lay wires. This type of interference ht or interlockoccasioned by wire 26 being formed with the serrations, as described, isto be contrasted with the case where such an inner surface of wire issmooth and in which event it is relatively more easy for the wire to bedisplaced relative to the subadjacent long lay wires under the drivingloads imposed by a driving member such as gear ld.

In an illustrated form of the subject invention as shown in FIGURE 1, a`therrnocouple device 26 is shown secured to one end of cable ld. Inthis case the thermocouple device may be clamped to and supported fromthe cable in any suitable manner such as through a tapered, externallythreaded collar member 2S and a coacting nut Sil which clamps thethermocouple to the cable. insulated lead wires 32 and 34 supportedwithin cable lil extend within thermocouple 2d and are essentially freeof any compressien or tension loads. Being thus free of alternatetension and compression loads, electrical lead wires 32 and 34 will besubjected to little or no wear and in this way greatly increasing thelife of the system with which they are utilized.

Referring to FIGURES 4 and 5, in a similar manner, cable itl may supporta tubular member 36 therewithin in a non-load carrying condition in theevent the cable were to be used in a situation where it is desired totransmit fluid materials therethrough.

lt is apparent that many uses may be made of the drivable hollow cableconstructed in accordance with the abovedescribed invention.

We claim:

l. A hollow drivable cable adapted to be movably supported within aconduit, said cable comprising a flat closely coiled inner member theadjacent convolutions of which are adapted to be in abuttingrelationship, a plurality of wire members laid about said inner coilwith a relatively long helix, a stiff wire element tightly wrapped aboutsaid plurality of wire members and in a direction opposite to the leadof said plurality of wire members, the diameter of said wire elementbeing at least twice the diameter of any one of said plurality of wiremembers, the adjacent convolutions of said wire element being equallyspaced longitudinally of said cable, said Wire element being adapted totransmit a longitudinal driving force to said cable, said wire elementincluding an inner surface adapted to contact a portion of the outer surfaces of said plurality of wire members, one of said contacting surfacesbeing formed to provide an interlocking Contact between said wireelement and said plurality of wire members tending to resist relativelongitudinal movement between said wire element and said plurality ofwire members during the application of said longitudinal driV- ing forceto said wire element.

2. A hollow drivable cable as set forth in claim 1 in which the surfaceof said wire element contacting said plurality of wire members isdeformed so as to form a discontinuous surface to provide saidinterlocking contact between said wire element and said plurality ofwire members.

3. A hollow drivable cable as set forth in claim 2 in which the surfaceof said wire element contacting said plurality of wire members comprisesa plurality of serrations extending transversely of the longitudinalaxis of s aind wire element.

4. A hollow drivable cable as set forth in claim l which includes adevice secured to one end of and supported by said cable, and mattertransmitting means supported within said closely coiled inner member formovement with said cable, said means being operatively connected to saiddevice in a load-free relationship, tension and compression loads beingcarried by the plurality of long helix wire members and the closelycoiled inner member.

5. A hollow drivable cable as set forth in claim 4 in which the surfaceof said wirc element contacting said plurality of wire members isdeformed so as to form a discontinuous surface to provide saidinterlocking contact between said wire element and said plurality ofwire members.

6. A hollow drivable cable as set forth `in claim 5 and which includes agear element adapted to coact with the convolutions of said wire elementto drive said cable.

(References on following page) 5 6 References Cited by the Examiner YFOREIGN PATENTS 717,945 10/31 France. UNITED STATES PATENTS 740,31811/32 France. 1,951,723 3/34 Burd et a1. 74-501 437,194 10/35 GreatBrltain- 5 870,683 6/61 Great Britain. 74 501 607,496 s/6o Italy.

DON A. WAITE, Primary Examiner.

2,187,873 1/40 Bratz 2,725,713 12/55 Blanchard. 2,998,696 9/61 Payer57-145 BROUGHTON G. DURHAM, Examiner.

www( T I UNITED STATES PATENT OFFICE CERTIFICATE OF CRRECTION Patent No.May 25,

Andrew J Kompanek, JT, et al.

It s hereby certified that error appears in the above numbered patentreqlring cerrecton and that the said Letters Patent should read ascorrectedbelow.

Column l, line 63, for "the" read and (SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER AI lastingOfficer

1. A HOLLOW DRIVABLE CABLE ADAPTED TO BE MOVABLY SUPPORTED WITHIN ACONDUIT, SAID CABLE COMPRISING A FLAT CLOSELY COLIED INNER MEMBER THEADJACENT CONVOLUTIONS OF WHICH ARE ADPATED TO BE IN ABUTTINGRELATIONSHIP, A PLURALITY OF WIRE MEMBERS LAID ABOUT SAID INNER COILWITH A RELATIVELY LONG HELIX, A STIFF WIRE ELEMENT TIGHTLY WRAPPED ABOUTSAID PLURALITY OF WIRE MEMBERS AND IN A DIRECTION OPPOSITE TO THE LEADOF SAID PLURALITY OF WIRE MEMBERS, THE DIAMETER OF SAID WIRE ELEMENTBEING AT LEAST TWICE THE DIAMETER OF ANY ONE OF SAID PLURALITY OF WIREMEMBERS, THE ADJACENT CONVOLUTIONS OF SAID WIRE ELEMENT BEING EQUALLYSPACED LONGITUDINALLY OF SAID CABLE, SAID WIRE ELEMENT BEING ADAPTED TOTRANSMIT A LONGITUDINAL DRIVING FORCE TO SAID CABEL, SAID WIRE ELEMENTINCLUDING AN INNER SURFACE ADAPTED TO CONTACT A PORTION OF THE OUTERSURFACES OF SAID PLURALITY OF WIRE MEMBERS, ONE OF SAID CONTACTINGSURFACES BEING FORMED TO PROVIDE AN INTERLOCKING CONTACT BETWEEN SAIDWIRE ELEMENT AND SAID PLURALITY OF WIRE MEMBERS TENDING TO RESISTRELATIVE LONGITUDINAL MOVEMENT BETWEEN SAID WIRE ELEMENT AND SAIDPLURALITY OF WIRE MEMBERS DURING THE APPLICATION OF SAID LONGITUDINALDRIVING FORCE TO SAID WIRE ELEMENT.